/********************************************************************
Created:	2012/04/14  20:16
Filename: 	RLib_MD5.cpp
Author:		rrrfff
Url:	    http://blog.csdn.net/rrrfff
 *********************************************************************/
#include "RLib_MD5.h"
using namespace System::Security::Cryptography;
//////////////////////////////////////////////////////////////////////////
#define S11 7
#define S12 12
#define S13 17
#define S14 22
#define S21 5
#define S22 9
#define S23 14
#define S24 20
#define S31 4
#define S32 11
#define S33 16
#define S34 23
#define S41 6
#define S42 10
#define S43 15
#define S44 21
static unsigned char PADDING[64] = 
{
    0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};
#define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
#define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
#define H(x, y, z) ((x) ^ (y) ^ (z))
#define I(x, y, z) ((y) ^ ((x) | (~z)))

#define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))

#define FF(a, b, c, d, x, s, ac)\
{\
(a) += F((b), (c), (d)) + (x) + (unsigned int)(ac);\
(a) = ROTATE_LEFT((a), (s));\
(a) += (b);\
}

#define GG(a, b, c, d, x, s, ac)\
{\
(a) += G((b), (c), (d)) + (x) + (unsigned int)(ac);\
(a) = ROTATE_LEFT((a), (s));\
(a) += (b);\
}

#define HH(a, b, c, d, x, s, ac)\
{\
(a) += H((b), (c), (d)) + (x) + (unsigned int)(ac);\
(a) = ROTATE_LEFT((a), (s));\
(a) += (b);\
}

#define II(a, b, c, d, x, s, ac)\
{\
(a) += I((b), (c), (d)) + (x) + (unsigned int)(ac);\
(a) = ROTATE_LEFT((a), (s));\
(a) += (b);\
}

static void md5_encode(unsigned char *output, unsigned int *input, int len)
{
    int i, j;
    for (i = 0, j = 0; j < len; i++, j += 4)
    {
        output[j] = (unsigned char)(input[i] &0xff);
        output[j + 1] = (unsigned char)((input[i] >> 8) &0xff);
        output[j + 2] = (unsigned char)((input[i] >> 16) &0xff);
        output[j + 3] = (unsigned char)((input[i] >> 24) &0xff);
    }
}

//-------------------------------------------------------------------------

static void md5_decode(unsigned int *output, unsigned char *input, int len)
{
    int i, j;
    for (i = 0, j = 0; j < len; i++, j += 4)
    {
        output[i] = ((unsigned int)input[j]) | (((unsigned int)input[j + 1]) << 8) | (((unsigned int)input[j + 2]) << 16) | (((unsigned int)input[j + 3]) << 24);
    }
}

//-------------------------------------------------------------------------

static void md5_transform(unsigned int state[4], unsigned char block[64])
{
    unsigned int a = state[0], b = state[1], c = state[2], d = state[3], x[16];
    md5_decode(x, block, 64);
    /* Round 1 */
    FF(a, b, c, d, x[0], S11, 0xd76aa478); /* 1 */
    FF(d, a, b, c, x[1], S12, 0xe8c7b756); /* 2 */
    FF(c, d, a, b, x[2], S13, 0x242070db); /* 3 */
    FF(b, c, d, a, x[3], S14, 0xc1bdceee); /* 4 */
    FF(a, b, c, d, x[4], S11, 0xf57c0faf); /* 5 */
    FF(d, a, b, c, x[5], S12, 0x4787c62a); /* 6 */
    FF(c, d, a, b, x[6], S13, 0xa8304613); /* 7 */
    FF(b, c, d, a, x[7], S14, 0xfd469501); /* 8 */
    FF(a, b, c, d, x[8], S11, 0x698098d8); /* 9 */
    FF(d, a, b, c, x[9], S12, 0x8b44f7af); /* 10 */
    FF(c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */
    FF(b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */
    FF(a, b, c, d, x[12], S11, 0x6b901122); /* 13 */
    FF(d, a, b, c, x[13], S12, 0xfd987193); /* 14 */
    FF(c, d, a, b, x[14], S13, 0xa679438e); /* 15 */
    FF(b, c, d, a, x[15], S14, 0x49b40821); /* 16 */
    /* Round 2 */
    GG(a, b, c, d, x[1], S21, 0xf61e2562); /* 17 */
    GG(d, a, b, c, x[6], S22, 0xc040b340); /* 18 */
    GG(c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */
    GG(b, c, d, a, x[0], S24, 0xe9b6c7aa); /* 20 */
    GG(a, b, c, d, x[5], S21, 0xd62f105d); /* 21 */
    GG(d, a, b, c, x[10], S22, 0x2441453); /* 22 */
    GG(c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */
    GG(b, c, d, a, x[4], S24, 0xe7d3fbc8); /* 24 */
    GG(a, b, c, d, x[9], S21, 0x21e1cde6); /* 25 */
    GG(d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */
    GG(c, d, a, b, x[3], S23, 0xf4d50d87); /* 27 */
    GG(b, c, d, a, x[8], S24, 0x455a14ed); /* 28 */
    GG(a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */
    GG(d, a, b, c, x[2], S22, 0xfcefa3f8); /* 30 */
    GG(c, d, a, b, x[7], S23, 0x676f02d9); /* 31 */
    GG(b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */
    /* Round 3 */
    HH(a, b, c, d, x[5], S31, 0xfffa3942); /* 33 */
    HH(d, a, b, c, x[8], S32, 0x8771f681); /* 34 */
    HH(c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */
    HH(b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */
    HH(a, b, c, d, x[1], S31, 0xa4beea44); /* 37 */
    HH(d, a, b, c, x[4], S32, 0x4bdecfa9); /* 38 */
    HH(c, d, a, b, x[7], S33, 0xf6bb4b60); /* 39 */
    HH(b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */
    HH(a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */
    HH(d, a, b, c, x[0], S32, 0xeaa127fa); /* 42 */
    HH(c, d, a, b, x[3], S33, 0xd4ef3085); /* 43 */
    HH(b, c, d, a, x[6], S34, 0x4881d05); /* 44 */
    HH(a, b, c, d, x[9], S31, 0xd9d4d039); /* 45 */
    HH(d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */
    HH(c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */
    HH(b, c, d, a, x[2], S34, 0xc4ac5665); /* 48 */

    /* Round 4 */
    II(a, b, c, d, x[0], S41, 0xf4292244); /* 49 */
    II(d, a, b, c, x[7], S42, 0x432aff97); /* 50 */
    II(c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */
    II(b, c, d, a, x[5], S44, 0xfc93a039); /* 52 */
    II(a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */
    II(d, a, b, c, x[3], S42, 0x8f0ccc92); /* 54 */
    II(c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */
    II(b, c, d, a, x[1], S44, 0x85845dd1); /* 56 */
    II(a, b, c, d, x[8], S41, 0x6fa87e4f); /* 57 */
    II(d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */
    II(c, d, a, b, x[6], S43, 0xa3014314); /* 59 */
    II(b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */
    II(a, b, c, d, x[4], S41, 0xf7537e82); /* 61 */
    II(d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */
    II(c, d, a, b, x[2], S43, 0x2ad7d2bb); /* 63 */
    II(b, c, d, a, x[9], S44, 0xeb86d391); /* 64 */

    state[0] += a;
    state[1] += b;
    state[2] += c;
    state[3] += d;

    memset((char*)x, 0, sizeof(x));
}

//-------------------------------------------------------------------------

void MD5::Initialize(MD5Context *context)
{
    context->count[0] = context->count[1] = 0;

    context->state[0] = 0x67452301;
    context->state[1] = 0xefcdab89;
    context->state[2] = 0x98badcfe;
    context->state[3] = 0x10325476;
}

//-------------------------------------------------------------------------

void MD5::HashCore(MD5Context *context, unsigned char *buf, int len)
{
    int i, index, partLen;

    index = (unsigned int)((context->count[0] >> 3) &0x3F);

    if ((context->count[0] += ((unsigned int)len << 3)) < ((unsigned int)len << 3))
    {
        context->count[1]++;
    }
    context->count[1] += ((unsigned int)len >> 29);

    partLen = 64-index;

    if (len >= partLen)
    {
        memcpy((char*) &context->buffer[index], (char*)buf, partLen);
        md5_transform(context->state, context->buffer);

        for (i = partLen; i + 63 < len; i += 64)
        {
            md5_transform(context->state, &buf[i]);
        }

        index = 0;
    }
    else
    {
        i = 0;
    }

    memcpy((char*) &context->buffer[index], (char*) &buf[i], len - i);
}

//-------------------------------------------------------------------------


void MD5::HashFinal(MD5Context *context, unsigned char digest[16])
{
    unsigned char bits[8];
    unsigned int index, padLen;

    md5_encode(bits, context->count, 8);

    index = (unsigned int)((context->count[0] >> 3) &0x3f);
    padLen = (index < 56) ? (56-index): (120-index);
    HashCore(context, PADDING, padLen);

    HashCore(context, bits, 8);

    md5_encode(digest, context->state, 16);

    memset((char*)context, 0, sizeof(*context));
}

//-------------------------------------------------------------------------

void MD5::ComputeHash(const void *buffer, int count, OUT byte output[16])
{
    MD5Context context;
    Initialize(&context);
    HashCore(&context, (unsigned char*)buffer, count);
    HashFinal(&context, output);
}

//-------------------------------------------------------------------------

System::String MD5::GetHashCode(System::String str, int length /* = 0 */)
{
	if (length > 0)
	{
		str = str.Substring(0, length);
	} //if
    byte md5_buffer[16];
    ComputeHash(str.ToMultiByte(), str.GetMultiByteSize(), md5_buffer);
    char md5_string[16 *2+1];
    md5_string[16 *2] = '\0';
    for (int i = 0, j = 0; i < 16; i++)
    {
        #pragma warning(disable:4995)
        sprintf(&md5_string[j], "%02x", md5_buffer[i] &0xFF);
        j += 2;
    }
    return System::String(md5_string);
}
System::String MD5::GetHashCode(LPCVOID Data, int DataByte)
{
	byte md5_buffer[16];
	ComputeHash(Data, DataByte, md5_buffer);
	TCHAR md5_string[16 *2+1];
	md5_string[16 *2] = T('\0');
	for (int i = 0, j = 0; i < 16; i++)
	{
#pragma warning(disable:4995)
		wsprintf(&md5_string[j], T("%02x"), md5_buffer[i] &0xFF);
		j += 2;
	}
	return System::String(md5_string);
}